"The Veil"

"The sight of [Aisha] riding into Medina on Safwan's camel had branded itself into the collective memory of the oasis, and that was the last thing Muhammad needed. In due course, another Quranic revelation dictated that from now on, his wives were to be protected by a thin muslin curtin from the prying eyes of any men not their kin. And since curtains could work only indoors, they would soon shrink into a kind of minicurtain for outdoors: the veil.

The Revelation of the Curtain clearly applied only to the Prophet's wives, but this in itself gave the veil high status. Over the next few decades it would be adopted by women of the new Islamic aristocracy - and would eventually be enforced by Islamic fundamentalists convinced that it should apply to all women."

- excerpt from "After the Prophet"

This is referring to the Affair of the Necklace, in which Aisha (one of Mohammed's wives) lost her necklace and went to find it, and came back and her caravan was gone without her. She strangley decided to wait for them to come back and get her (though the pack did not go very far without her). They never did come back for her, and a random, galliant man (Safwan) picked her up and took her to where she needed to be.

This was harmful to Mohammed's stately affairs, which were important at the time for the influence of Islam. There were rumors that she did something shameful with this youthful, strapping man, and it therefore was harmful to Mohammed's reputation (directly relating to how his political affairs were handled).